Vacuum dryer for bactrol weight control system

ABSTRACT

APPARATUS FOR DEHYDRATING THE CONTENTS OF A BAG, SAID APPARATUS HAVING A HEATING CHAMBER INCLUDING A CHAMBER HAVING A PRESSURE PLATE FOR BRINGING THE BAG INTO CONTACT WITH A HEATING UNIT WHEN THE CHAMBER IS CLOSED AND A VALVE RESPONSIVE TO THE DIFFERENTIAL PRESSURE BETWEEN THE INTERIOR OF THE BAG AND THE CHAMBER FOR CONTROLLING THE VENTING OF THE EFFLUENT VAPOR TO A LOW PRESSURE AREA. THE APPARATUS ALSO INCLUDES A VALVE RESPONSIVE TO THE CONDITION OF THE SEAL OF THE APPARATUS TO PREVENT THE ATMOSPHERE OUTSIDE OF THE APPARATUS FROM BEING EVACUATED THROUGH THE CHAMBER TO THE LOW PRESSURE AREA.

3,564,726 VACUUM DRYER FOR BACTROL WEIGHT CONTROL SYSTEM 7 Feb. 23,1971J. NQ|T| ET AL 2 Sheets-Sheet 1 Filed Dec.

Mm A OIT T W N Cw EOG V N W H m @A ATTORNEY-S United States Patent3,564,726 VACUUM DRYER FOR BACTROL WEIGHT CONTROL SYSTEM John M. Nocitiand Anthony Giotta, New York, N.Y., assignors to Fail-child HillerCorporation, Hagerstown, Md., a corporation of Maryland Filed Dec. 26,1967, Ser. No. 693,291 Int. Cl. F26b 2I/06 US. Cl. 34-51 11 ClaimsABSTRACT OF THE DISCLOSURE Apparatus for dehydrating the contents of abag, said apparatus having a heating chamber including a chamber havinga pressure plate for bringing the bag into contact with a heating unitwhen the chamber is closed and a valve responsive to the differentialpressure between the interior of the bag and the chamber for controllingthe venting of the eflluent vapor to a low pressure area. The apparatusalso includes a valve responsive to the condition of the seal of theapparatus to prevent the atmosphere outside of the apparatus from beingevacuated through the chamber to the low pressure area.

This invention relates to drying apparatus and more particularly toapparatus for drying human waste products as well as other debris toremove their liquid content.

In many applications, it is desirable to dehydrate human waste productssuch as feces and urine to reduce the weight of the material and also,if desired, to permitretention of the solid constituents for laterlaboratory analysis. The problem of the limited space available in aspace vehicle prohibits the retention of such waste material except in adried form. Although a major application for waste dehydration is inconnection with space flight, drying of waste material under conditionsto keep the atmosphere free of contamination is also of use in hospitalsor other analytical facilities.

The present invention is directed to use with the bag disclosed in thepatent application entitled Waste Collection Bag described in andclaimed in the co-pending application Ser. No. 613,031 filed Ian. 31,1967 by Nociti and Riely and assigned to the same assignee. Theapparatus of the present invention includes a chamber for re ceiving thebag containing waste material. The chamber has at least one surfacecapable of heating the bag and its contents to evaporate the liquid fromthe waste and is vented to vacuum so that etlluent vapor produced by theheating can be removed. A valve is also provided which is adapted toreact to excess pressure across the bag to close the vent to vacuum andto permit pressure within the chamber to equalize with the pressure inthe bag. Further the apparatus also includes, when used in a spacecraft,means to prevent the accidental opening of the chamber while the chamberis vented to vacuum and consequent loss of the cabin atmosphere.

The invention will be described in greater detail below and in thedrawings in which:

FIG. 1 is a perspective view partially broken away of the dryingapparatus of the present invention;

FIG. 2A is a partial cross-section along lines 22 of FIG. 1 showing thevalve 46 vented to vacuum;

FIG. 2B is a partial cross-section along line 22 of FIG. 1 showing thevalve 46 vented to the cabin;

FIG. 3 is a cross-sectional view of the drying apparatus of FIG. 1,showing one of the chambers in an open position ready to receive a bagand one in an operating position; and

FIG. 4 is a partial cross-section along line 4-4 of FIG. 3 showing plate40 of valve 37.

3,564,726 Patented Feb. 23, 1971 r. CC

Referring to FIGS. 1 and 3, the drying apparatus illustrated includesfour individual drying chambers 10-1, 102, 10-3 and 104, each of whichis similar. Fewer or more chambers can be used as desired. Each of thechambers has exterior side walls 11a, b, c and d and a bottom wall 112which may be welded along any seam therein so as to be impervious to thepassage of gases and also structurally capable of withstanding thedifferential pressure created by vacuum within the chamber and cabinpressure without. As shown, two chambers may have a common wall 11d. Thechambers may be cast as well as stamped from sheet material in anyconventional manner.

The top of each chamber is provided with a door 12 which is affixed bymeans of hinges 13 to side wall 11a of the chamber. Located at the topof the chamber and extending inwardly from the side walls 11a, b, c, d,is a flange 14. Flange 14 is sealed to the side Walls with an imperviousseam and is provided with a flat surface on its top side for receiving agasket 16 which is afiixed to the underside of door 12. When door 12 isin its closed position, gasket 16 rests on flange 14 and forms a seal toprevent gases from entering or leaving the chamber.

Located in communication with adjacent side walls 11c of a pair ofdehydrating chambers 10 is a heat exchanger 17. The heat exchanger issubstantially the same size as wall of each chamber and includes abaflle arrange ment 17a which extends the length of wall 11a and whichin the embodiment shown may extend the entire length of two chambers topermit one heat exchanger to heat all four chambers. Bafiles 17a arecorrugated to provide even distribution of the heating fluid. An intakeline 18 (FIG. 3) located at one end of baflies 17a permits hot Water orheated vapor or gas from some portion of an external system (not shown)to enter the heat exchanger. The fluid heating medium passes upwardlyalong a space provided at the edge of the heat exchanger from line 18and then passes through the baffles 17a. The cool liquid or vapor isvented through outlet 19 at the lower opposite end of the exchanger. Theend of heat exchanger 17 near outlet 19 is provided with a space betweenthe bafiies 17a and the end wall to permit complete draining of thecooled fluid.

Located interior to each of the chambers and parallel to wall 11a is apressure plate 20 (FIG. 3) which engages a waste collection bag 21, whenin place in the unit, and forces it against the heat exchanger. One formof bag 21 that may be used in connection with the apparatus of thisinvention is shown in FIG. 3. The bag has an impermeable outer wall 58containing an opening 57 located on one side. A filter 56 is mountedinterior to the bag and covers opening 57 to prevent loss of the solidconstituent of the waste material during evaporation. Other forms ofbags may be used with this apparatus having filters located in otherportions of their surfaces or no filter at all. The plate 20 is biasedtoward the exchanger 17 by two springs 22. Each spring 22 has the end ofone arm 22a fixed to the interior of Wall 11a and the end of the otherarm 23 to the back of the pressure plate.

Aflixed to the side of each door 12 on the side interior of the chambernear its edge is a pair of parallel plates 24 which extend generallyperpendicularly to each door and which are also generally perpendicularto heat exchanger 17. Each of the plates 24 contains a slot 25substantially parallel to the door 12. A pin 26 aflixed to the end ofeach of a pair of pressure plate retractors 27in the chamber rides inthe slot. Pressure plate retractors 27 which may be flat bars of alength slightly smaller than the height of a chamber are mounted on apair of parallel arms 28 and 29 which are pivotally mounted at one oftheir ends 30', 31 to wall 11a of the chamber. Pressure plate retractors27 are located so that they are between the edges of plate 20 and theend wall. Parallel arm 28 is pivotally mounted at its other end to pin26 and arm 29 is pivotally mounted at end 32 to the retractor. When door12 is closed arms 28 and 29 and, in turn, plate retractors 27 are cammedby pin 26 forward toward the heat exchanger 17. Upon opening of door 12a reverse camming OCCUIS.

A pair of pins 34 permanently aflixed to the rear outside, oppositeedges of pressure plate 20 engages a pair of horizontal guides 33aifixed to opposite end walls 11b and 11d of a chamber. Guides 33 andpins 34 prevent the pressure plate from moving vertically whilepermitting it to move freely toward and away from the wall 11c of thechamber common to the heat exchanger 17.

When door 12 is opened the pressure plate retractors 27 are cammedtoward wall 11a by arms 28 and 29 and in turn retractors 27 engage pins34 outside of plate 20 between the plate and the side walls, drawing thepressure plate into an open position away from the heat exchanger. Whendoor 12 is closed the retractors 27 are urged toward the heat exchanger17 disengaging from pins 34 and permitting springs 22 to bias thepressure plate against a collection bag 21.

Affixed to the interior of wall 11a of the chamber on the side oppositeheat exchanger 17 is a valve housing 35. Housing 35 is generally oftubular shape and is provided with an inwardly extending flange 36 atits end interior to the chamber. The housing is mounted in a hole 35alocated in the wall of the chamber and is also provided with an exteriorflange 35b which seals the hole. A valve 37 is mounted in housing 35.Valve 37 is provided with a tubular body 38 and contains a plate 40which closes the interior end of the valve. A series of apertures 39 arecircumferentially located near the closed end of tubular body 38adjacent plate 40 (see FIG. 4). Plate 40 is also provided with a seriesof apertures 41 which are aligned with a similar pattern of apertures 42in the pressure plate 20. A spring 44 biases valve 37 toward thepressure plate. The opposite end of spring 44 abuts against a plug 45which is mounted in the end of housing 35 opposite valve 37. The innerend of valve 37 located within housing 35 contains an outwardlyextending flange 43 which engages flange 36 to limit the travel of thevalve toward the pressure plate 20.

Mounted on plug 45 exterior of the chamber is a control valve 46 (seeFIGS. 2A and 2B). Control valve 46 contains an outer chamber 47 having ahollow space therein which is in communication with aperture 48 in plug45. Located in the hollow space is a ball 48a which contains a passage49 having a 90 bend in one plane. A pair of openings 50 and 51 inhousing 47 are located opposite each other and 90 from aperture 48 inthe same plane so that when ball '48 is in one position as shown in FIG.2A aperture 48 is in communication with opening 51 and when the ball isrotated 90 as shown in FIG. 2B aperture 48 is in communication withopening 50. Opening 50 is vented to atmospheric pressure which in thecase of a spacecraft is cabin pressure while opening 51 is vented toline 51a shown in FIG. 2 which leads to a manifold 51b and a vent line510 to vacuum which in the case of a spacecraft will be the exterior ofthe vehicle.

Affixed to ball 48a is a rod 52 (see FIGS. 1 and 3) which is rotatablymounted in bracket 53 affixed to the exterior of wall 11a. Aflixed tothe top end of rod 52 is a closure bar 54 which contains a handle 55 atthe opposite end from rod 52. Ball 48a and closure handle 54 arearranged so that when bar 54 is generally parallel to wall 11a of thechamber permitting door 12 to open, valve 46 will be vented to the cabinas shown in FIG. 213 to permit equalization of the pressure inside andoutside of the chamber to permit the chamber to be open. Valve 46 canonly be vented to vacuum when closure bar '54 is located in a positionover door 12 preventing the door from opening. This prevents accidentalloss of 4 pressurization in the cabin of a spacecraft through vent ingof the cabin air to space through valve 46.

In operation closure bar 54 is rotated to its open position to permitvalve 46 to vent the chamber to the cabin (see FIG. 3 left-handcompartment) and a bag 21 containing waste materials which are requiredto be dehydrated is inserted in one of the chambers between wall 110 andpressure plate 20. Opening 57 which is covered by filter 56 is alignedwith pressure plate 20 so that the opening is over holes 42 as shown inFIG. 4. At this point in the sequence of operations, the pressure platewill be retracted by the pressure plate retractors 27 thereby permittingentry of the bag.

After the bag is in place door 12 is closed, thereby camming thepressure plate retractors 27 toward the heat exchanger releasingpressure plate 20' and allowing it to move against the collection bagstabilizing the bag in a vertical position and insuring positive contactbetween the bag and the wall 110 in contact with the heat exchanger. Asthe pressure plate 20 moves away from wall 11a valve 37 moves under theinfluence of spring 44 inwardly into the chamber exposing thecircumferential valve openings 39 to the interior of the chamber. Atthis point in the operation with door 12 closed and the bar 54 in theposition shown in the left-hand chamber in FIG. 1, valve 46 is stillvented to cabin pressure so that no change in the pressurization of thechamber occurs. Closure bar 54 is then rotated into a locking positionover door 12 preventing door 12 from opening. At the same time as door12 is locked valve 46 is opened to vacuum causing a decrease in pressurewithin the chamber. Heated fluid or vapor is then caused to pass throughheat exchanger 17 heating the contents of bag 21. Means (not shown) maybe provided to automatically start the heating cycle or a valve in theinlet line 18 may be opened. As the heat is applied gases and vaporsevolved by the heating process pass outwardly through bag filter 56,opening 57 and holes 41 and 42 into the chamber. Such gases will thenpass through openings 39 in valve 37 and then into space throughaperture 48 and lines 51a, 51b and 510.

During the course of the drying of the material which may take severalhours the pressure differential between the interior and exterior of thebag may increase within bag 21 to the point where it will cause ruptureof filter 56 and loss of the contents of the bag into the chamber. Aspressure increases, however, bag 21 swells and forces the pressure plate20 further away from the heat exchanger 17. At the same time plate 40 ofvalve 37 will also be forced within body 35 until apertures 39' areclosed by flange 36. When this occurs the venting to vacuum ceases andpressure from the gases within bag 21 will fill the space of chamber 10until the pressures inside and outside of the bag are equalized. Whenthis occurs the springs 22 will move pressure plate 20 to once againforce bag 21 against the heat exchanger permitting apertures 39 to openand the dehydrating process to resume with the vapors venting to theexterior of the chamber.

When the process of dehydration has been completed as may be indicatedby a timer 15 affixed to the unit the heat flow through the heatexchanger is stopped by closure of a valve (not shown) and the gases inthe unit are permitted to continue their evacuation to space. After asuitable period handle 55 is grasped and rod 52 is turned shutting thevent 46 to space and opening the chamber to the cabin atmosphere causingthe pressure within the chamber to be equalized with the cabin pressure.Door 12 may then be opened and bag 21 removed and a new bag inserted.When the pressure plate is in its retracted position it will causeapertures 39 of valve 37 to be closed by flange 36 of housing 35providing an additional safety feature to prevent loss of cabin pressureto space.

As is apparent a novel dehydration device has been disclosedparticularly adapted to the dehydration of Waste materials wherecontamination of the area surrounding the chamber must be prevented. Thedevice, being particularly adapted to use in spacecraft, prevents theinadvertent loss of cabin atmosphere while providing a relatively simpleoperational cycle.

While a preferred embodiment of the invention has been disclosed above,it will be understood that this is illustrative only, and the inventionis limited solely by the appended claims.

What is claimed is:

1. A dehydrating unit for use in dehydrating the contents of a flexiblebag, comprising in combination a housing having a receiving chamber forsaid bag, means for sealing said chamber, means for heating the contentsof said bag, means for positioning said bag within said chamber withrespect to said heating means, means for venting the vapor within saidchamber evolved by said heating to an area of lower pressure than saidchamber, means responsive to the pressure differential between theinterior and exterior of said bag to control the means for venting saidchamber and means responsive to the sealing of said chamber to preventthe loss of atmosphere outside of said chamber to the source of lowerpressure.

2. A dehydrating unit according to claim 1 wherein the means to preventthe loss of atmosphere outside of said chamber to the source of lowerpressure comprises a valve controlling the means for venting the chamberto the low pressure source, means for controlling the position of saidvalve, operating means for controlling the position of the valve whenthe chamber is sealed whereby the air outside of said chamber isprevented from venting to said low pressure source when said chamber issealed.

3. A dehydrating unit according to claim 2 wherein said means to preventchamber venting further includes means to equalize the pressure betweenthe low pressure exterior to said chamber and the pressure interior ofthe chamber.

4. A dehydrating unit for use in dehydrating the contents of acontainer, comprising in combination a housing defining a chamber forreceiving said container, means for sealing said chamber, means forheating the contents of said container, means for venting the gas withinsaid chamber evolved by said heating to a source of lower pressure thansaid chamber, and means responsive to the pressure differential betweenthe interior of said container and said chamber to control the means forventing the chamber.

5. A dehydrating unit as in claim 4 wherein said con- 50 tainer has anexit port and said means for venting the gas evolved comprises means incommunication with the container exit port.

6. A dehydrating unit as in claim 4 wherein the container is of aconstruction so as to change its size in response to the said pressuredifferential as moisture is removed therefrom, and said means responsiveto said pressure differential comprises valve means which is operated bythe change in size of said container.

7. A dehydrating unit according to claim 6 wherein said valve includes avalve housing afiixed to the interior of a wall of the housing definingsaid chamber, a valve body having a sealed end and a plurality ofapertures adjacent 5 said sealed end, said body and housing beingslidably mounted with respect to each other with said sealed end towardthe interior of the chamber, means for connecting said valve to saidsource of low pressure, and means for biasing said valve body outwardlyfrom said valve housing to clear the apertures of said valve body'whereby when a container is positioned with a portion thereof incontact with said valve body an increase in the differential pressurebetween said container and said chamber causing the container to expandin size will move the valve body to close said valve.

8. A dehydrating unit as in claim 6 wherein said container has an exitport and said means for venting the gas evolved comprises said valvemeans which includes means for receiving the gas evolved through thecontainer exit port.

9. A dehydrating unit for use in dehydrating the contents of a flexible,variable size container comprising in combination a housing defining achamber for receiving said container, means for sealing said chamber,means for heating the contents of said container, means for venting thegas within said chamber evolved by said heating to a source of lowerpressure than said chamber, and means for maintaining contact betweenthe heating means and the container when the unit is unsealed.

10. A dehydrating unit according to claim 9 further including means fordisengaging said means for maintaining contact between the container andthe means for heating the contents of said container when said unit isunsealed.

11. A dehydrating unit according to claim 10 wherein said means formaintaining contact and for disengaging comprises a movable pressureplate substantially parallel to the means for heating said container,means for urging said plate toward said heating means, and meansresponsive to the position of the chamber sealing means for urging saidplate away from said heating means when said chamber is unsealed.

References Cited UNITED STATES PATENTS 906,459 12/1908 Ortiz 34-923,118,742 1/ 1964 Dalgleish et al 34-143XY FOREIGN PATENTS 1,091,95811/1954 France 34-92 202,586 8/ 1923 Great Britain 34-51 FREDERICK -L.MATTESON, JR., Primary Examiner H. B. RAMEY, Assistant Examiner US. Cl.X.R. 34-242

